Effective and efficient methods for facilitating widespread application of optimal cancer prevention and early detection technologies are poorly defined. While educational programs that focus on the benefits of different counseling and technical interventions, directed to both health professional and patient/consumer groups, are a conventional approach, it has been difficult to measure and demonstrate program efficacy. Because primary care physicians have frequent contact (average 3 visits per year) with many patients, and their offices are the usual sites where prevention services are provided, this audience is an optimal target for intervention. From experience in conducting a randomized trial of four educational interventions with groups of primary care physicians, we have developed efficient and reliable methods for measuring the delivery of preventive services, and an innovative educational program to be tested with a variety of physician groups. In the proposed research, 120 primary care physicians who are members of 24 clinic or hospital educational meeting groups in the upper Midwest will be recruited. Physicians in communities with minority and elderly populations will be targeted. Physicians will be asked to allow identification of a random sample of 37 male and 37 female patients, 51 1/2-73 1/2 years old, in their practices to whom a brief questionnaire will be sent that contains questions about prevention services received in the past 18 months. Following this, groups will be randomly assigned to receive either: 1) summaries of patient reports by individual physicians; or 2) summaries of patient reports by individual physicians plus three educational meetings on site. The educational meetings will focus on explicit definition of community/group consensus on cancer prevention services, and specific practice policies and activities to the initially cancer-free responders. In targeting systems for the delivery of cancer prevention services by primary cue physicians, this educational intervention focuses on the critical 'place-of-delivery' step in the provision of optimal prevention services. If this relatively brief, on-site educational intervention is demonstrated to be effective, there is great potential to transfer this model to other primary care health care delivery systems and to other health problems that require primary and secondary prevention strategies.